iStockphoto/Thinkstock(CHICAGO) -- A manhunt is underway after two bank robbers escaped from their Chicago jail cell by breaking through the window and scaling down the building with a makeshift rope of bed sheets and blankets.

An upstairs neighbor told landlord Ron Bailey that Banks and Conley showed up at the home and Conley's mother took a gun away from him before they left, WLS reported.

The FBI stormed the house but believe they missed the escapees by only a few hours. FBI spokesperson Joan Hyde said the two bank robbers should be considered "armed and dangerous."

Banks, 37, and Conley, 38, were being held at the Metropolitan Correctional Center, a federal jail, in downtown Chicago. Police say the two men, who were cellmates, were last seen in the jail Monday at 10 p.m. during a head count.

In an FBI affidavit filed Tuesday night, authorities say sometime after the head count the two men stuffed their beds with clothes in the shape of bodies and broke the window inside their cell. They squeezed through the window and scaled down more than 20 stories using rope made of bed sheets, towels and blankets.

To cover up their escape, Banks and Conley made fake bars to put over the five-inch wide window and placed the actual metal bars inside a mattress, according to the affidavit.

Police did not realize the men had escaped until approximately 7 a.m. Tuesday when arriving employees noticed the rope that led the men to freedom still dangling from the building.

Four elementary schools and a middle school were put on a soft lockdown and all after school activities were canceled after police got word the escapees were spotted in Tinley Park, WLS reported.

Hyde said that the trail has since gone cold, and that no one should take matters into their own hands if Banks and Conley are spotted.

Banks is a notorious bank robber known as the Second-Hand Bandit because he wore used clothes during his heists. He was convicted last week of robbing two banks and attempting to rob two others. Court records show that he stole less than $600,000 and more than $500,000 of it is still missing.

Banks represented himself in court, had to be restrained at one point and vowed he would seek retribution, telling the judge, "You'll hear from me," WLS reported.

Conley was scheduled to be sentenced on Jan. 10 after he pleaded guilty of robbing $4,000 from a bank, according to WLS.